Speed-indicator.



No. 669,457. Patented Mar. 5, l90l.

`a. c. uAvlsoN. A SPEED INDIGATUR.

(Applimmn med sep. 27, 1900,)

4(No Nudel.)

III-111i Unrrnn Sra'rns GREGORY CALDWELL DAVISON, OF THE UNITED STATES NAVY.

SPEED-INDICATOR.

SPECIFICATION forming part of Letters Patent No. 669,457, dated March 5, 1901.

Application fled September 27, 1900. Serial. No. 31,300. (No model.)

To @ZZ whom, it may concern.-

Be it known that I, GREGORY CALDWELL DAVISN, lieutenant United States Navy, stationed at New York, in the county of New York and State of New York, have invented certain new, and useful Improvements in Speed-Indicators; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in devices for indicating the speed of a rotating shaft; and it has for its object to produce a speed-indicator of this class which may be used for accurately determining the speed of rotation of a shaft in various sorts of Inachinery.

My invention, broadly stated, consists the employment of a loosely-mounted spherical body which is given rotation from a shaft whose velocity of rotation is constant and known and also given a rotation at right angles to the rotation of said constant shaft from the shaft the speed of rotation of which is to be measured.

The details and the arrangements of parts are hereinafter fully described and are illustrated in the accompanying drawings, Wherein the same parts are indicated by the same letters throughout both views.

Figure l represents a top plan view of the apparatus for indicating the speed of rotation of a shaft; and Fig. 2 is a View in side elevation looking toward the top of the sheet, parts being shown in section.

A represents a light hollow true sphere,pref erably of such metal as brass or aluminium.

B represents a disk rotating in a vertical plane and making frictional contact with the surface of the sphere A. The disk B is fixed upon a shaft B', and the latter is mounted in fixed antifriction-bearings B2. The shaft B corresponds to the shaft the speed of rotation of which is to be measured, and this shaft may be connected to the shaft whose speed of rotation is to be measured by any convenient or suitable way.

O represents a disk rotating in a vertical plane at right angles to the plane of rotation of the disk B and making frictional contact with the surface of the sphere A. The disk inl C is fixed upon a shaft C', which is mounted in stationary antifriction-hearings C2. The shaft O is geared in any suitable way, such as shown in the drawings, to a clockwork mechanism operated by a spring C3 or any other suitable means of propulsion by means of which a rotation may be given to the shaft O' and the disk O thereon. In order to render the speed of the shaft C' uniform, a governor, composed of flexible arms O4, carrying weights O5, is mounted upon the shaft C. One end of each of the arms C4 is fixed to a boss or disk C6, fixed upon the shaft C', and the opposite ends of said flexible arms O4 are fixed to a sleeve C7, mounted loosely upon the shaft C'. A brake-disk C8 is connected to the sleeve O7, and fixed near the upper face of the brake-disk O8 is a plate O9, so that an excessive speed of the shaft O' will be arrested by the friction of the brake-disk Os against the fixed plate O9 by reason of the said brakedisk being drawn toward the plate upwardly by the bending of the'fiexible arms O4, due to the weights O5 flying outwardly by the force of the rotation of the shaft O. By this arrangement of the governor the speed of rotation of the shaft C may be made practically uniform and constant, and this is esssential, inasmuch as the speed of rotation of the shaft B is to be determined by comparison with the speed of rotation of this shaft O.

D and E represent disks or wheels mounted in fixed antifriction bearings D2 and E2. These disks D and E are located opposite the disks B and O, respectively, and the planes of rotation correspond to the planes of rotation of the said disks B and C, as will be clearly seen in Fig. l of the drawings. The disks B and O serve merely as guides for the Asphere A. The sphere A is mounted rup in a small idle disk F, carried in a support F', having antifriction-bearingsf, which permit of a rot-ation in a horizontal plane of the disk F and its support F. The support F of the disk 'F is provided with an arm F2, rigid therewith, and in the end of which arm is mounted an idle disk F3, which also is arranged to rotate in contact with the surface of the sphere. The idle disk F8, mounted in the arm F2 on the support F of the idle disk F, serves, by reason of its frictional contact with the surface of the revolving sphere, to

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maintain the axis of rotation of the idle disk F parallel to the axis of rotation of the sphere.

H represents a graduated arm, and I represents a pointer or index-arm hinged at I to a pin I2, pivoted to rotate in a cross-arm or support I3. The index arm or pointer I is so hinged to the pivot-pin I2 as to rotate in a horizontal plane therewith and be capable of a swinging movement in a vertical plane.

An idle disk or roller I4, mounted in bearings I5, carried by the index arm or pointer I, is arranged to rotate in ,frictional contact with the surface of the sphere A, as is shown in Fig. 2 of the drawings, and a spring I(s is provided for exerting adown ward pressure upon the index arm or pointer I, thus increasing the friction between the disk or roller I4 and the surface of the sphere.

The operation of the device is as follows: Assuming that the shaft B and the disk B thereon, as well as the disks D and E, are idle, rotation of the shaft O/ and the disk C thereon in contact with the surface of the sphere causes the sphere to roll or revolve about a horizontal axis at right angles to the plane of rotation of the disk C, it being understood that the direction of rotation of the disk C and its shaft C is lthat indicated by the arrow c in Fig. 2, which will cause a rotation of the sphere in the direction of the arrow d, also seen in Fig. 2. During this rolling of the sphere A under the action of the disk O alone the disks B and D will remain stationary and the guide-disk E and the supporting disk or roller F and its follower-disk F3, as also the disk or roller I4 on the index-pointer, will be caused to rotate by frictional contact with the surface of the sphere. The disk or roller F3 will follow the plane of rotation of the sphere, as will also the roller I4 on the index-pointer, and the roller I4, following the plane of rotation of the sphere, causes the pointer I, in the case above assumed, to stand at the intermediate point on the graduated arc H. It should be understood that the rotation of the disk C may be continuous and is always in the same direction. Now assume that the shaft B and the disk B thereon be caused to rotate by connection with a rotating shaft the speed of rotation of which is to be measured. This rotation of the disk B in contact with the surface of the sphere in a plane at right angles to the plane of rotation of the disk (l causes the plane of rotation of the sphere toshift from a plane parallel with the axis of rotation of the disk C. If the shaft B and the disk B be rotated, the plane of rotation of the sphere will be shifted to an angle intermediate between the plane of rotation of the disks C and B and the degree of variation in the plane of rotation of the sphere will depend upon the comparative speeds of rotation of the disk C and the disk B. The rotation of the disk B in one direction causes the shifting of the plane of rotation of the sphere to the left, while the rotation of the disk .Bl in the opposite direcpoint.

tion causes the shifting of the plane of rotation of the sphere in the opposite direction from its intermediate plane of rotation coinaiding with the plane of rotation of the disk C. As the plane of rotation of the sphere shifts the roller I4, having frictional contact with the surface of the sphere, causes the pointer I to shift its direction and follow the plane of rotation of the sphere to the right or left of its central point, as shown in Fig. l, according to the direction of rotation ofthe disk B. The arc H would be graduated from the central point in opposite directions to correspond with the variationsin speed intended to beindicated thereon. From the foregoing it will be seen that the greater the speed of rotation ofthe disk B as compared with the speed of rotation of the disk C the greater will be the variation of the plane of rotation of the sphere, and consequently the greater will be the movement of the point of the index-arm I to the one side or the other of its central or zero Thus if the speed of rotation of the disk B be exactly equal to the speed of rotation of the disk C the pointer I will assume a position on the graduated arc exactly onehalf way between its Zero or intermediate point and one end of the arc, according to the direction of the rotation of the disk B.

The graduations and markings on the arc H in practice may readily be laid out upon the graduated scale by computing the angles of variation for varying speeds of the surface of the sphere .contacting with the disk B, the speed of the disk C, and consequently the speed of rotation of that portion of the surface ofthe sphere in contact therewith being known.

I do not wish to limit myself to the centrifugal governor for the shaft C herein shown and described, as this form of governor is shown merely for the purposes of illustration, and it may be preferable to vary the style of the governor used to suit conditions. Thus on shipboard a centrifugal governor would be unsatisfactory and some other style would be used to give more satisfactory results.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is-

1. In a speed-indicator, the combination witha loosely-mounted rotatable sphere; and means for imparting to said sphere a rotation tending to a predetermined plane; of means for communicating to the said sphere the rotative speed to be measured, at an angle to the plane in which the sphere tends to rotate; and means for indicating the variations in the plane of rotation of the sphere, substantially as described.

2. In a speed-indicator, the combination with a freely-supported sphere; a disk making contact with the surface of said sphere; and means for imparting to the said disk a uniform speed; of adisk making contact with the surface of said sphere and arranged to IOO Ifo

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rotate in a plane at right angles to the plane of rotation of the first disk, the speed of rotation of the first disk being known, and the speed of rotation of the second disk being variable; and means for indicating the variations in the plane of rotation of the sphere due to the comparative speeds of the two disks, substantially as described.

3. In a speed-indicator, the combination with a loosely-mounted rotatable sphere; and means for imparting to said sphere a rotation tending to a predetermined plane; of means for communicating to the said sphere the rotative speed to be measured at an angle to the plane in which the sphere tends to rotate; a pivoted pointer or index-arm; and a roller carried by said pointer or index-arm making frictional contact with the surface of the sphere and arranged to follow the plane of rotation of the said sphere, substantially as described.

4. In a speed-indicator, the combination with aloosely-mounted rotatable sphere; and means for imparting to said sphere a rotation tending to a predetermined plane; of means for communicating to the said sphere the rotative speed to be measured at an angle to the plane in which the sphere tends to rotate; a graduated arc; a pivoted pointer or indexarm; and a roller carried by said pointer or index-arm making frictional contact with the surface of the sphere and arranged to follow the plane of rotation of the said sphere, substantially as described.

5. In a speed-indicator, the combination with aloosely-mounted rotatable sphere; antif riction bearings supporting said sphere; and means for imparting to said sphere a rotation tending to a predetermined plane; of

means for communicating to the said sphere the rotative speed to be measured, at an angle to the plane in which the sphere tends to rotate; and means for indicating the variations in the plane of rotation of the sphere, substantially as described.

6. In a speed-indicator, the combination with a loosely mounted rotatable sphere; means for imparting to said sphere a rotation tending to a predetermined plane; and means for guiding said sphere; of means for communicating to the said sphere/the rotative speed to be measured, at an angle to the plane inwwhich the sphere tends to rotate; and means for indicating the variations in the plane of rotation of the sphere, substantially as described.

7. In a speed-indicator, the combination with a freely-supported sphere; a rotatable disk making contact with the surface of said sphere; a motor for rotating said disk; and a governor controlling the speed thereof; of a disk of variable speed making contact with the surface of said sphere and arranged to rotate in a plane at right angles to the plane of rotation of the first disk; and means for indicating the variations in the plane of rotation of the sphere due to the comparative speeds of the two disks, substantially as described.

8. In a speed-indicator, the combination with a loosely-mounted rotatable sphere; antifriction-bearings supporting said sphere; and means for imparting to said sphere a rotation tending to a predetermined plane; of means for communicating to the said sphere the rotative speed to be measured, at an angle to the plane in which the sphere tends to rotate; a pivoted pointer or index-arm; and a roller carried by said pointer or index-arm making i frictional contact with the surface of the sphere, and arranged to follow the plane of rotationof the said sphere, substantially as described.

9. In a speed-indicator, the combination witha loosely-mounted rotatable sphere, and a frictional device forimparting to said sphere a rotation tending to a predetermined plane; of a frictional device for communicating to the said sphere the rotative speed to be measured, at an angle to the plane in which the sphere tends to rotate; a graduated arc; a pivoted pointer or index-arm; and a roller carried by said pointer or index-arm making frietional contact with the surface of the sphere and arranged to follow the plane of rotation of the said sphere, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

GREGORY CALDWELL DAVISION.

Witnesses:

PAUL C. CHILD, H. A. SHERMAN. 

